UDEC60常用命令集锦

rest

delete range -2,2 -2,2

reset disp reset hist hist

un bal hist ydis 0,2 step

2000

plot hold block stress disp

；

位移归

0

edge

Example 3.2 EJfta rtrundit^ latglh on crack getteraiion

ro

D

.2

；

ro

D .

1

bi 0.0 o

f

io i0

f

in lo.o cr 0,3.0

9.7

f

10

]f the rounding length ia reduced (o O.

I

.

then the crack will be located where sfyecified.

I lie

SET edge

command allows the user to Ueiine

a minimum blxKvd*

亡

kngch nianually. With

Thisconimana, the u^er

匚日

n set a small rnunding length for solution accuracy bur avoid blocks with

small edg

亡

lengths and, consequently, adversel} high aspect ratios (see below). For exajnpk. if

Lhe

SET edge

0.4

and

ROUND 0.1

arc $$pe

(

;ifk

也

then block

、

tnal< /p>

吐山

an G4

VrilL ilol be cruaicMl. and the rounding length for blocks

ill

be OJ. These coinnunds be

gi

en beLor^tlie

BLOCK

coinmaiid.

Joints jregion

jset angle 135 trace 1 gap 2 spacing 1.732 origin 0.259,0.966 range jreg 1 jregion

2

joints

jset angle jset

0 trace 1

gap 2 spacing 1

?

732 origin

Q

a

0 range jreg 2

0 trace 1

gap

2

spacing 1.732 origin 1

?

5.0.866 range jreg 2

angle

jset angle 60 trace 1 gap 2 spacing 1

?

732 origin 1.0 range jreg 2

jset angle 60 trace 1 gap 2 spacing 1

?

732 origin. 1.1.732 range jreg 2

Joints that are joined are assigned high values for normal and shear stiffness. It is tempting to

give

VCQ

high values for stiffnesses to prevent movement along a fictitious joint. 1 lowcvcr, the

timestep calculation

in

UDEC

is based upon stiffnesses; the response (and solution convergence) will be very slow if very

high siifTncsses are spexified. Tlic lowest MifTiiess consisieni with small joint deformaiion is used

when joints are joined. The rule-of-thumb is that joint stifTnesse s

t

I

n

and

k

s

.

should be set to a factor

times the equivalent stiffness of the stiffest neighboring zone.

The

equation to calculate fictitious

joint normal stiffness related to the equivalent stiffness (expressed in stress-per-distance units) of a

zone in the normal direction is of the form

k

n

= f actor

x max

(3.1)

Figure 3.14 Zone dimension used ui stiffness calculation

Systems of Units

2.S Systems of L'nils

UDEC

accepts any con listen

f

of engineering units, Examples of consis

：

enr sets of units for

h

阳

it parameters are shown in

Table 2.5.

The user should be very careful when converting from one stem

of uniK to unoiher. An excellent reference on the subject or units and conversion between the Imperiikl

and

SI

s stems can be iimnd in the

Juunuti

(DecCEiiber 1977

)

. No conveniions

are perfomicd in

L

DEC

except for firictiun jnd diLatiun angles,

M

hich arc entered in degrees.

Table 2.5 Sysleuta of units

-

mechanical parameters

SI

Imperial

m

IO

6

kg/m

1

MN

ME

m/sec

【工哩

ih

Den

HQ

Foree

m

kg/Hi'

1

N

內

Stress

m

11? kg/in

1

kN

kPa

m/scc

cm

Mdyfies

bar

cnJs*

ft

tlugt/ft

3

呵

in

di bJ in

Ibf

P

点

ft/sec^

in/sec^

(Iraviij

m/sec

7

where

1

bar

1 atm

=

10^ dynes! cm- = 1()^ N/ni-

=

1,013 bars

=

14.7 psi

=

2U6

=

1(P Pa;

lb

(

/ft

2

=

1.01325 x 10

s

Pa

；

1

slug

=

1 Lbj

—

s- / ft = 14.59 kg

；

I

snail

=

1

Ib|-

—

in: and

I

gravity = 9.81 ni/s

:

= 9S1 cm/s

2

=32.17 ft/s

3

.

Hist

hist solve type 1

solve rat 1e-5

save tun

hist ydis 42 -67 sxx 42 -67

hist ydis 42 -73 sxx 42 -73 reset disp jdisp

solve rat 1e-5

save tun

Plot

pl syy fill projected pl syy fill bfill

JOS 1TTLE

:

UDEG VwsiQfi

Fi

却球

X27

Stress ertnfou rs using

PLOT syy fill projected

pl ydisp fill

pl bl id black

plot pen stress block

显示应力

pen

作用是

udec4.0

窗口显示

pl se

看裂隙

pl